Mare Nubium

Mare Nubium
Name	Mare Nubium
Type	Lunar mare
Coordinates	15.0°S 17.0°W
Diameter	715 km
Surface area	~282,000 km²
Notable craters	Bullialdus, Pitatus, Thebit

Mare Nubium is a lunar mare on the near side of the Moon, occupying a broad basin surrounded by highland terrain and impact rings. It forms part of the series of basaltic plains that include other maria such as Mare Imbrium, Mare Serenitatis, Mare Tranquillitatis, and Mare Humorum, and it has been studied in connection with sample-return missions like Apollo 11, Apollo 12, and Luna 16. Observations from telescopes operated at institutions such as the Royal Observatory, Lick Observatory, Mount Wilson Observatory, and spacecraft from agencies including NASA, Roscosmos, ESA, and ISRO have contributed to its mapped geology.

Location and Physical Characteristics

Mare Nubium lies in the southwestern quadrant of the near side, bordered by formations such as Mare Cognitum, Oceanus Procellarum, Mare Insularum, and the highlands near the Lacus Somniorum region. Prominent rim and basin features include the impact basins related to craters like Bullialdus, Thebit, Pitatus, Gassendi, and Phocylides. Its coordinates place it within lunar quadrangles cataloged by the USGS Astrogeology Science Center and mapped in lunar atlases produced by the Lunar and Planetary Institute, Jet Propulsion Laboratory, and the Clementine and LROC imaging teams. Mare Nubium’s albedo contrasts with neighboring terrains cataloged by surveys led by Giovanni Riccioli-era nomenclature and later standardized by the International Astronomical Union.

Geology and Composition

The mare basalts are compositionally similar to basalts sampled from regions like Mare Tranquillitatis and Oceanus Procellarum, with titanium, iron, and magnesium contents measured by missions such as Lunar Reconnaissance Orbiter, Clementine, Chandrayaan-1, and Kaguya (SELENE). Remote sensing from the Moon Mineralogy Mapper, Diviner radiometer, and gamma-ray spectrometers on Lunar Prospector and Chang'e spacecraft have identified mare units, pyroclastic deposits, and mare basalt flows, and have been compared against returned samples curated by the Smithsonian Institution and analyzed at institutions including Caltech, MIT, University of Arizona, and the Max Planck Institute for Solar System Research. Petrologic studies referencing work by researchers at Brown University, University of New Mexico, Imperial College London, and Université Paris-Sud classify the basalt types and their crystallization histories.

Formation and Age

Stratigraphic relationships between impact craters and mare units reveal emplacement ages derived from crater counting and radiometric analogs informed by Apollo sample ages. Mare basalts across the near side, including those in this basin, formed predominantly in the Imbrian and Eratosthenian periods, contemporaneous with basaltic flooding observed in Mare Imbrium and Mare Humorum, with age constraints compared to radiometric dates from Apollo 15, Apollo 16, Apollo 17, and Luna 24. Geological models developed at Caltech, Brown University, and the Smithsonian Astrophysical Observatory tie mare formation to mantle melting episodes influenced by basin-scale impacts analogous to events inferred from the Giant Impact Hypothesis and global maria-forming episodes documented in stratigraphies mapped by USGS and Istituto Nazionale di Astrofisica teams.

Observational History and Naming

Telescopic observations from observers such as Galileo Galilei, Johannes Hevelius, Giovanni Battista Riccioli, Wilhelm Beer, Johann Heinrich Mädler, and Giovanni Schiaparelli contributed to early mapping and nomenclature, later formalized by the International Astronomical Union and used in atlases by Ewen A. Whitaker and the USGS lunar nomenclature group. Photographic surveys by E. E. Barnard, Percival Lowell, and photographic plate programs at Harvard College Observatory plus modern digital mosaics from Clementine, LRO, and Kaguya have refined the mare’s extent. Historical accounts link lunar mapping advances to institutions like the Royal Society, Académie des Sciences, and the Royal Astronomical Society.

Exploration and Mapping

Robotic and crewed missions that imaged or sampled nearby maria, including Surveyor 3, Luna 16, Luna 20, and Apollo-era orbiters, provided comparative datasets used by teams at NASA JPL, NASA MSFC, ESA ESOC, CNSA, and ISRO to refine geologic maps. High-resolution mapping campaigns by the Lunar Reconnaissance Orbiter Camera team, spectral mapping by Chandrayaan-1 and Moon Mineralogy Mapper teams, and gravity mapping from GRAIL have produced detailed gravity, topography, and composition maps used in studies at MIT, Brown University, University of Hawaii, and Smithsonian Astrophysical Observatory. Cartographic products appear in atlases published by Cambridge University Press, Springer, and the USGS.

Notable Features and Surrounding Formations

Key craters and formations bordering the mare include Bullialdus to the west, Pitatus to the northeast, Thebit and Thebit A complex to the east, and the Hippalus rille systems and wrinkle ridges that tie into regional tectonic patterns observed near Mare Cognitum and Oceanus Procellarum. Secondary basaltic units, domical constructs, and pyroclastic deposits have been correlated with features studied in comparative analyses involving Tycho, Copernicus, Clavius, Schiller, and Rimae Hyginus, and contextualized within broader lunar geology research programs at Lunar and Planetary Institute, Smithsonian Institution, and Caltech.

Category:Lunar maria